1. Field of the Invention
The present invention relates to a compact automotive air conditioner and, more particularly, to an air duct selector used in such a device.
2. Description of the Related Art
Conventional temperature controlling methods of an automotive air conditioner can be roughly classified into two groups; that is, a reheat system and an air mix system. Firstly, in the reheat system, an evaporator and a heater core are arranged in an air duct to completely close the air passage in the duct. By adjusting a heating power of the heater core, a desired air temperature is achieved. In the other system, i.e., in the air mix system, a bypass passage in which air passing through an evaporator detours around a heater core is installed, and the ratio of air passing through the bypass passage to that passing through the heater core is adjusted by the air mix door to provide a desired air temperature.
Incidentally, the reheat system and the air mix system have both good points and bad points. In the reheat system, because a space accommodating the air mix door is not needed, the size of the air conditioner becomes smaller. However, in the reheat system, because the air passing through the evaporator always passes through the heater core, air resistance is increased, and a required amount of mixed air cannot be obtained when the heating power of the heater core is zero, for example.
In the other system, i.e., in the air mix system, in a maximum cooling mode, because the air is not sent to the heater core, the air resistance can be decreased. However, in the air mix system, because space is needed for rotating the air mix door, there is a problem in that the size of the air conditioner becomes larger.
A conventional system has been disclosed in which the air resistance is not increased and the size of the air conditioner itself is not increased to control the air temperature, for example, in Japanese Patent Publication Laid-Open No. Hei 4-257720. In that system, opening and closing of an air passage and mixing of the warm air and the cool air are controlled by a thin film member, and miniaturization of the air conditioner is achieved.
However, in such a conventional air conditioner, because a drive shaft is needed for doing storage and rewind at the end of the film (similar to a film canister), there are problems in that the air conditioner needs a large number of components and the cost becomes very high.
Further, an air conditioner is disclosed in Japanese Utility Model Laid-Open Publication No. Hei 6-71222 in which the air mix door is not a rotating system, but instead is a sliding door which vertically slides relative to a direction of air flow, and thereby a ratio of cool air to warm air is controlled.
However, in the above-described sliding door of the air conditioner, though a mixing ratio of cool air to warm air is controlled by the sliding door, for example, in the maximum cooling mode, there is a problem in that cooling power is decreased when a space between the sliding door and the casing of the air conditioner is not entirely sealed as the air is leaked through the slide door to the heater core. Besides, in Japanese Utility Model Laid-Open Publication No. Hei 6-71222, a sealing structure is not installed between the sliding door and the air conditioning case, and the structure cannot be sealed for practical use.
Thus, it is conceivable that the space between the sliding door and the air conditioning case may be sealed by a seal on the sliding door, for example. However, when such a seal is put on the sliding door and the sliding door simply moves in a straight line, because the seal is pressed against the air conditioning case, there is a problem in that the amount of force required to control the sliding door becomes larger. Further, the seal may come off by repeated actuation of the sliding door; therefore the sliding door air does not adequately seal the air passage.